Gilead Announces Data From Two Studies Supporting Further Development of GS-6207, a Novel, Investigational HIV-1 Capsid Inhibitor as a Component of Future Long-Acting HIV Therapies

FOSTER CITY, Calif.--(BUSINESS WIRE)--Mar. 7, 2019--
Gilead Sciences, Inc. (NASDAQ:GILD) today announced findings from two
studies that support the further development of GS-6207, a novel,
selective, first-in-class inhibitor of HIV-1 capsid function, for
potential future use as part of long-acting HIV combination therapy.
Interim blinded data from a Phase 1 study in healthy trial participants
demonstrated that single doses of GS-6207 of up to 450 mg, administered
subcutaneously, achieved sustained concentration levels and were
well-tolerated. Separately, in vitro data demonstrated picomolar
potency with GS-6207, including against HIV strains resistant to other
antiretroviral (ARV) classes. The data were presented at the 2019
Conference on Retroviruses and Opportunistic Infections (CROI) in
Seattle (Session O-06).

“These studies indicate that GS-6207, a first-in-class, investigational
capsid inhibitor, may represent a novel approach to HIV treatment due to
its long-acting characteristics and potent antiviral activity seen in
vitro,” said John McHutchison, AO, MD, Chief Scientific Officer and
Head of Research and Development, Gilead Sciences. “The data presented
at CROI support advancing GS-6207 to the next phase of clinical trials
to gain a deeper understanding of its potential role as a long-acting
agent for people living with HIV.”

GS-6207 was evaluated in 40 healthy trial participants in an ongoing
Phase 1 randomized, blinded, placebo-controlled, safety, tolerability
and PK study. The participants were randomized (4:1) in four staggered
single dose escalation cohorts to receive GS-6207 (n=8/cohort) or
placebo (n=2/cohort), at 30, 100, 300 or 450 mg. Through 20 weeks (30 mg
cohort) to 4 weeks (450 mg cohort) of study, there were no deaths,
serious adverse events (AEs) or Grade 3 or 4 AEs. Most AEs were mild
(Grade 1) and resolved. PK parameters for the 30 mg and 100 mg cohorts
have been estimated; analyses for the 300 mg and 450 mg cohorts are
ongoing. The PK profile of subcutaneously administered GS-6207 is
consistent with sustained delivery, supporting a dosing interval of at
least 3 months at doses greater than 100mg.

The in vitro study evaluated the pharmacological profile of
GS-6207 – which demonstrated up to >100-fold greater potency than
certain commonly prescribed ARVs and synergistic antiviral activity when
combined with the ARVs tenofovir alafenamide, efavirenz, dolutegravir or
darunavir. The in vitro study also demonstrated that GS-6207
retains full potency against a broad range of HIV-1 strains resistant to
other ARV classes.

Gilead has initiated a Phase 1b study of GS-6207 in people living with
HIV.

GS-6207 is an investigational therapy and not approved by any regulatory
body globally; its safety and efficacy have not been established. There
is no cure for HIV or AIDS.

About Gilead Sciences

Gilead Sciences, Inc. is a research-based biopharmaceutical company that
discovers, develops and commercializes innovative medicines in areas of
unmet medical need. The company strives to transform and simplify care
for people with life-threatening illnesses around the world. Gilead has
operations in more than 35 countries worldwide, with headquarters in
Foster City, California.

For nearly 30 years, Gilead has been a leading innovator in the field of
HIV, driving advances in treatment, prevention, testing and linkage to
care, and cure research. Today, it’s estimated that more than 11.5
million people living with HIV globally receive antiretroviral therapy
provided by Gilead or one of the company’s manufacturing partners.

For more information on Gilead Sciences, please visit the company’s
website at www.gilead.com.

Forward-Looking Statement

This press release includes forward-looking statements within the
meaning of the Private Securities Litigation Reform Act of 1995 that are
subject to risks, uncertainties and other factors. In addition, we may
have difficulties conducting the Phase 1b clinical study of GS-6207 as
currently anticipated. In addition, we may observe unfavorable results
from additional studies GS-6207 and Gilead may make a strategic decision
to discontinue development of GS-6207 if, for example, Gilead believes
commercialization will be difficult relative to other opportunities in
its pipeline. As a result, GS-6207 may never be successfully
commercialized. These risks, uncertainties and other factors could cause
actual results to differ materially from those referred to in the
forward-looking statements. The reader is cautioned not to rely on these
forward-looking statements. These and other risks are described in
detail in Gilead’s Annual Report on Form 10-K for the year ended
December 31, 2018, as filed with the U.S. Securities and Exchange
Commission. All forward-looking statements are based on information
currently available to Gilead, and Gilead assumes no obligation to
update any such forward-looking statements.

Gilead and the Gilead logo are trademarks of Gilead Sciences, Inc. or
its related companies.

For more information on Gilead Sciences, please visit the company’s
website at www.gilead.com,
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or call Gilead Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.